We request continued participation in the NICHD Cooperative Neonatal Research Network. Our major strengths include: l) A large patient population. In 1994 we had 16,742 births, 291 VLBW infants, and 1450 neonatal ICU admissions (97% inborn). Full and effective participation of our infants in Network trials is fostered by our faculty's conservative treatment philosophy. 2) A highly qualified PI. Dr. Tyson has extensive experience in multicenter trials, unusual expertise in experimental design, and an uncommon knowledge of "cutting edge" issues in health policy, health care economics, and outcomes research. He is not only Professor of Pediatrics and Obstetrics at UT Southwestern in Dallas but also Adjunct Professor of Epidemiology at the School of Public Health in Houston where he was Visiting Professor at the Health Policy Institute during 1993-1994. 3) A strong track record in the Network. We have ranked high in both percent of eligible infants enrolled and in total enrollment in Network studies during the past 10 years. Our PI has contributed heavily and has designed the next major trial, a trial that will last approximately 16 months and bridge the 2 funding periods. For the next funding period, he has proposed a major trial endorsed by the Steering Committee to reduce resource use, trauma, radiation, and nosocomial infection among infants equal to or less than 1000 g BW. 4) Other major strengths. These include a) a highly productive neonatal division; b) a perinatal collaborator who is quite experienced in large management trials and the PI in an application to the Perinatal Network; c) an extensive and well organized neonatal data base of proven value to the Network; and d) a follow-up clinic that has excelled in not only observational studies but also major trials of follow-up interventions, e.g. the Primary Care Trial (funded by the Agency for Health Care Policy and Research) and the Infant Health and Development Program (funded by NICHD and the Robert Wood Johnson Foundation).